Transponders exist in the market which may be used for various animal applications (e.g., for tracking/individual identification of companion animals, fish, slaughter animals, etc.). These transponders include passive RFID (radio frequency identification) transponders, which may be encapsulated in glass or other similarly durable material, and can be implanted directly in the animal (e.g., using a syringe). Such transponders are described, for example, in U.S. Pat. No. 5,211,129, which is incorporated herein by reference in its entirety.
Applicant has determined that transponders may also be used advantageously in implantable devices. Preferably, the transponder is incorporated into the device during its manufacture, and the device with transponder integrated therein is subsequently implanted into an animal or human.
However, the manufacture of implantable devices typically involves high temperatures, for example, about 150 to 210° C. (±20° C.). Existing transponders are not configured to withstand such conditions.
Heretofore, implantable transponders have needed only to operate at the body temperature of the animal in which they are implanted, and to withstand typical shipping/storage conditions. For example, existing transponders typically use microchips that are rated only to 80° C. for operation and to 125° C. for storage. In addition, existing transponders often use an anisotropic connection to connect the antenna leads to the microchip; this connection is made with glues that may fail at high temperatures. Testing has shown that existing transponders show an unacceptable rate of failure following high temperature exposure.
Thus, there is a need in the art for transponders that can withstand high temperature environments such as those used in manufacturing, without comprising the ability to store and retrieve data therefrom when used afterwards under normal operating conditions.